This invention is directed to dental crowns and dental and orthodontic appliances and enhancing their appearance for the patient by applying a polymeric, tooth-colored coating. Permanent crowns are often a tooth-colored dental ceramic which is tinted to blend with the rest of the teeth of a patient. When the patient has dental procedures in progress, an exposed portion of the tooth which is very sensitive has to be covered by a temporary crown. These crowns are made of malleable metal shells, which resemble the tooth to be replaced. The dentist has available temporary crowns which match the typical shape of various size of molars, bicuspids and other teeth which are in the process of dental restoration. Also available are aluminum temporary caps which are cylindrical without anatomy on a flat occlusal surface.
The temporary crown is worn during the time that a permanent crown is being made. The temporary crown is metallic usually of an aluminum, stainless steel, tin/silver alloy, other alloys or anodized metal. It is necessary to have a malleable material so that the temporary crown can be cut and trimmed to provide a comfortable bite on the occlusal surface of the opposite tooth. Also, the crown must be crimped around the base of the remaining portion of the tooth to provide a smooth, comfortable and secure fit.
The metal temporary crown used have an unattractive appearance. There are metallic crowns with a gold colored anodized layer, but this is not a tooth-colored layer which blends in appearance with the patient's teeth. This type of crown was disclosed in U.S. Pat. No. 3,422,535 in which the anodized layer to a metal crown provided an insulated coating to prevent discomfort due to galvanic action between the crown and other metals used for dental work such as silver fillings and gold restoration. The crown would have a metallic appearance with the gold-colored dye.
Another area of interest for natural looking appliances is the orthodontic and dental field. More and more adults as well as young people are turning to orthodontic correction. The appliances used in the mouth have been made of metallic materials that include bands which slip around the teeth, cleats which are glued on the front of the teeth and stainless steel wires which connect the various appliances to arrange the teeth in proper alignment. The metallic appliances are quite unattractive and recent improvements included use of clear polymer appliances with the stainless steel wires. Certain parts of dental appliances will benefit with a natural look. The wires used to hold partial plates can be coated to blend in with the patient's teeth.